2011年全国电子设计大赛D-LC谐振放大器(D题).doc

2011年全国大学生电子设计竞赛 题目： 《》 指导教师：参赛学生： 学 校： 院 系： LC谐振放大器设计与总结报告1. 频率较高 中心频率一般在几百KHZ到几百MHZ 频带宽度在几KHZ到几十MHZ，故必须用选频网络 2． 小信号 信号较小故工作在线性范围内即工作在线性放大状态。 3. 采用谐振回路做负载，即对靠近谐振频率附近的信号有较大的增益，对远离谐振频率附近的信号其增益迅速下降，即具有选频放大作用。 其主要用途： 无线电接收系统中高频和中频信号的放大。 Abstract： High-frequency small-signal amplifier is commonly used in Communications equipment functional circuit, it magnified a few hundred KHZ signal frequency to several hundred MHZ. High-frequency small-signal Amplifier function is to achieve high-frequency signals of weak distorted amplification, the signal contained in the spectrum from the point of view, the input signal spectrum and the spectrum of amplifier output signal is the same. High-frequency small-signal amplifier Category: Divided by components: transistor amplifiers, FET amplifiers integrate amplifiers Divided by band: narrowband amplifiers, broadband amplifiers From according to the circuit is divided into : single-stage amplifier, multi-stage amplifier; 4、According to the load are divided into : resonant amplifier, non-resonant amplifier; The high frequency small signal tuned amplifier is widely used in communications systems and radio systems , particularly in the transmitter of the receiver, the signal from the antenna on the sensor is very weak, which requires use of the amplifier to amplify. High-frequency signal amplifier theory is very simple, but the actual production is very difficult. One of the most prone to the problem is self-oscillation, and impedance matching between the frequency and levels of selection are also difficult to achieve. This article is based on theoretical analysis, based on the actual production, with the LC oscillation circuit for the assistance, to eliminate the high frequency amplifier self-oscillation and to achieve accurate frequency selection; plus other circuits, to achieve impedance matching amplifier and before and after class 1．方案设计与论证 1.1衰减器的选择 方案一：非线衰减网络，根据题目要求频带要与放大器相适应，则要求3dB带宽足够宽，特性阻抗保持50欧，这样时比较难达到的。 方案